/* $Xorg: utils.c,v 1.5 2001/02/09 02:05:24 xorgcvs Exp $ */
/*

Copyright 1987, 1998  The Open Group

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of The Open Group shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization
from The Open Group.


Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts,
Copyright 1994 Quarterdeck Office Systems.

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the names of Digital and
Quarterdeck not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior
permission.

DIGITAL AND QUARTERDECK DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS, IN NO EVENT SHALL DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT
OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE
OR PERFORMANCE OF THIS SOFTWARE.

*/
/* $XFree86: xc/programs/Xserver/os/utils.c,v 3.81 2002/01/16 20:39:51 dawes Exp $ */
#include <stdlib.h>

#include <X11/Xos.h>
#include <stdio.h>
#include "misc.h"
#include <X11/X.h>
#include "input.h"
#include "dixfont.h"
#include "osdep.h"
#ifdef X_POSIX_C_SOURCE
#define _POSIX_C_SOURCE X_POSIX_C_SOURCE
#include <signal.h>
#undef _POSIX_C_SOURCE
#else
#if defined(X_NOT_POSIX) || defined(_POSIX_SOURCE)
#include <signal.h>
#else
#define _POSIX_SOURCE
#include <signal.h>
#undef _POSIX_SOURCE
#endif
#endif
#include <sys/wait.h>
#include <sys/resource.h>
#include <time.h>
#include <sys/stat.h>
#include <ctype.h>    /* for isspace */
#include <stdarg.h>


#include <stdlib.h>	/* for malloc() */

#if defined(TCPCONN) || defined(STREAMSCONN)
#  include <netdb.h>
#endif

#include "opaque.h"

#ifdef SMART_SCHEDULE
#include "dixstruct.h"
#endif

#ifdef XKB
#include "XKBsrv.h"
#endif
#ifdef XCSECURITY
#define _SECURITY_SERVER
#include "security.h"
#endif

#define X_INCLUDE_NETDB_H
#include <X11/Xos_r.h>

#include <errno.h>

Bool CoreDump;
Bool noTestExtensions;

#ifdef PANORAMIX
Bool noPanoramiXExtension = TRUE;
Bool PanoramiXVisibilityNotifySent = FALSE;
Bool PanoramiXMapped = FALSE;
Bool PanoramiXWindowExposureSent = FALSE;
Bool PanoramiXOneExposeRequest = FALSE;
#endif

#ifdef DDXOSVERRORF
void (*OsVendorVErrorFProc)(const char *, va_list args) = NULL;
#endif

int auditTrailLevel = 1;

Bool Must_have_memory = FALSE;


#ifdef DEBUG
#ifndef SPECIAL_MALLOC
#define MEMBUG
#endif
#endif

#ifdef MEMBUG
#define MEM_FAIL_SCALE 100000
long Memory_fail = 0;
#include <stdlib.h>  /* for random() */
#endif


char *dev_tty_from_init = NULL;		/* since we need to parse it anyway */

OsSigHandlerPtr
OsSignal(sig, handler)
    int sig;
    OsSigHandlerPtr handler;
{
    struct sigaction act, oact;

    sigemptyset(&act.sa_mask);
    if (handler != SIG_IGN)
	sigaddset(&act.sa_mask, sig);
    act.sa_flags = 0;
    act.sa_handler = handler;
    sigaction(sig, &act, &oact);
    return oact.sa_handler;
}
	
#ifdef SERVER_LOCK
/*
 * Explicit support for a server lock file like the ones used for UUCP.
 * For architectures with virtual terminals that can run more than one
 * server at a time.  This keeps the servers from stomping on each other
 * if the user forgets to give them different display numbers.
 */
#define LOCK_DIR "/tmp"
#define LOCK_TMP_PREFIX "/.tX"
#define LOCK_PREFIX "/.X"
#define LOCK_SUFFIX "-lock"



#ifndef PATH_MAX
#include <sys/param.h>
#ifndef PATH_MAX
#ifdef MAXPATHLEN
#define PATH_MAX MAXPATHLEN
#else
#define PATH_MAX 1024
#endif
#endif
#endif

static Bool StillLocking = FALSE;
static char LockFile[PATH_MAX];
static Bool nolock = FALSE;

/*
 * LockServer --
 *      Check if the server lock file exists.  If so, check if the PID
 *      contained inside is valid.  If so, then die.  Otherwise, create
 *      the lock file containing the PID.
 */
void
LockServer()
{
  char tmp[PATH_MAX], pid_str[12];
  int lfd, i, haslock, l_pid, t;
  char *tmppath = NULL;
  int len;

  if (nolock) return;
  /*
   * Path names
   */
  tmppath = LOCK_DIR;

  len = strlen(LOCK_PREFIX) > strlen(LOCK_TMP_PREFIX) ? strlen(LOCK_PREFIX) :
						strlen(LOCK_TMP_PREFIX);
  len += strlen(tmppath) + strlen(display) + strlen(LOCK_SUFFIX) + 1;
  if (len > sizeof(LockFile))
    FatalError("Display name `%s' is too long\n");
  (void)sprintf(tmp, "%s" LOCK_TMP_PREFIX "%s" LOCK_SUFFIX, tmppath, display);
  (void)sprintf(LockFile, "%s" LOCK_PREFIX "%s" LOCK_SUFFIX, tmppath, display);

  /*
   * Create a temporary file containing our PID.  Attempt three times
   * to create the file.
   */
  StillLocking = TRUE;
  i = 0;
  do {
    i++;
    lfd = open(tmp, O_CREAT | O_EXCL | O_WRONLY, 0644);
    if (lfd < 0)
       sleep(2);
    else
       break;
  } while (i < 3);
  if (lfd < 0) {
    unlink(tmp);
    i = 0;
    do {
      i++;
      lfd = open(tmp, O_CREAT | O_EXCL | O_WRONLY, 0644);
      if (lfd < 0)
         sleep(2);
      else
         break;
    } while (i < 3);
  }
  if (lfd < 0)
    FatalError("Could not create lock file in %s\n", tmp);
  (void) sprintf(pid_str, "%10ld\n", (long)getpid());
  (void) write(lfd, pid_str, 11);
  /* 
   * Don't use chmod, ever. CVE-2011-4029: file permission change vulnerability.
   */
  (void) fchmod(lfd, 0444);
  (void) close(lfd);

  /*
   * OK.  Now the tmp file exists.  Try three times to move it in place
   * for the lock.
   */
  i = 0;
  haslock = 0;
  while ((!haslock) && (i++ < 3)) {
    haslock = (link(tmp,LockFile) == 0);
    if (haslock) {
      /*
       * We're done.
       */
      break;
    }
    else {
      /*
       * Read the pid from the existing file
       * Don't follow symlinks, CVE-2011-4028
       */
      lfd = open(LockFile, O_RDONLY|O_NOFOLLOW);
      if (lfd < 0) {
        unlink(tmp);
        FatalError("Can't read lock file %s\n", LockFile);
      }
      pid_str[0] = '\0';
      if (read(lfd, pid_str, 11) != 11) {
        /*
         * Bogus lock file.
         */
        unlink(LockFile);
        close(lfd);
        continue;
      }
      pid_str[11] = '\0';
      sscanf(pid_str, "%d", &l_pid);
      close(lfd);

      /*
       * Now try to kill the PID to see if it exists.
       */
      errno = 0;
      t = kill(l_pid, 0);
      if ((t< 0) && (errno == ESRCH)) {
        /*
         * Stale lock file.
         */
        unlink(LockFile);
        continue;
      }
      else if (((t < 0) && (errno == EPERM)) || (t == 0)) {
        /*
         * Process is still active.
         */
        unlink(tmp);
	FatalError("Server is already active for display %s\n%s %s\n%s\n",
		   display, "\tIf this server is no longer running, remove",
		   LockFile, "\tand start again.");
      }
    }
  }
  unlink(tmp);
  if (!haslock)
    FatalError("Could not create server lock file: %s\n", LockFile);
  StillLocking = FALSE;
}

/*
 * UnlockServer --
 *      Remove the server lock file.
 */
void
UnlockServer()
{
  if (nolock) return;

  if (!StillLocking){

  (void) unlink(LockFile);
  }
}
#endif /* SERVER_LOCK */

/* Force connections to close on SIGHUP from init */

/*ARGSUSED*/
SIGVAL
AutoResetServer (sig)
    int sig;
{
    int olderrno = errno;

    dispatchException |= DE_RESET;
    isItTimeToYield = TRUE;
#ifdef GPROF
    chdir ("/tmp");
    exit (0);
#endif
    errno = olderrno;
}

/* Force connections to close and then exit on SIGTERM, SIGINT */

/*ARGSUSED*/
SIGVAL
GiveUp(sig)
    int sig;
{
    int olderrno = errno;

    dispatchException |= DE_TERMINATE;
    isItTimeToYield = TRUE;
    errno = olderrno;
}

#if __GNUC__
static void AbortServer() __attribute__((noreturn));
#endif

static void
AbortServer()
{
    OsCleanup();
    AbortDDX();
    fflush(stderr);
    if (CoreDump)
	abort();
    exit (1);
}

void
Error(str)
    char *str;
{
    perror(str);
}

#ifndef DDXTIME
CARD32
GetTimeInMillis()
{
    struct timeval  tp;

    X_GETTIMEOFDAY(&tp);
    return(tp.tv_sec * 1000) + (tp.tv_usec / 1000);
}
#endif

void
AdjustWaitForDelay (waitTime, newdelay)
    pointer	    waitTime;
    unsigned long   newdelay;
{
    static struct timeval   delay_val;
    struct timeval	    **wt = (struct timeval **) waitTime;
    unsigned long	    olddelay;

    if (*wt == NULL)
    {
	delay_val.tv_sec = newdelay / 1000;
	delay_val.tv_usec = 1000 * (newdelay % 1000);
	*wt = &delay_val;
    }
    else
    {
	olddelay = (*wt)->tv_sec * 1000 + (*wt)->tv_usec / 1000;
	if (newdelay < olddelay)
	{
	    (*wt)->tv_sec = newdelay / 1000;
	    (*wt)->tv_usec = 1000 * (newdelay % 1000);
	}
    }
}

void UseMsg()
{
    ErrorF("use: X [:<display>] [option]\n");
    ErrorF("-a #                   mouse acceleration (pixels)\n");
    ErrorF("-ac                    disable access control restrictions\n");
#ifdef MEMBUG
    ErrorF("-alloc int             chance alloc should fail\n");
#endif
    ErrorF("-audit int             set audit trail level\n");	
    ErrorF("-auth file             select authorization file\n");	
    ErrorF("bc                     enable bug compatibility\n");
    ErrorF("+bs                    enable any backing store support\n");
    ErrorF("-bs                    disable any backing store support\n");
    ErrorF("-c                     turns off key-click\n");
    ErrorF("c #                    key-click volume (0-100)\n");
    ErrorF("-cc int                default color visual class\n");
    ErrorF("-co file               color database file\n");
#ifdef COMMANDLINE_CHALLENGED_OPERATING_SYSTEMS
    ErrorF("-config file           read options from file\n");
#endif
    ErrorF("-core                  generate core dump on fatal error\n");
    ErrorF("-dpi int               screen resolution in dots per inch\n");
#ifdef DPMSExtension
    ErrorF("dpms                   enables VESA DPMS monitor control\n");
    ErrorF("-dpms                  disables VESA DPMS monitor control\n");
#endif
    ErrorF("-deferglyphs [none|all|16] defer loading of [no|all|16-bit] glyphs\n");
    ErrorF("-f #                   bell base (0-100)\n");
    ErrorF("-fc string             cursor font\n");
    ErrorF("-fn string             default font name\n");
    ErrorF("-fp string             default font path\n");
    ErrorF("-help                  prints message with these options\n");
    ErrorF("-I                     ignore all remaining arguments\n");
#ifdef RLIMIT_DATA
    ErrorF("-ld int                limit data space to N Kb\n");
#endif
#ifdef RLIMIT_NOFILE
    ErrorF("-lf int                limit number of open files to N\n");
#endif
#ifdef RLIMIT_STACK
    ErrorF("-ls int                limit stack space to N Kb\n");
#endif
#ifdef SERVER_LOCK
    ErrorF("-nolock                disable the locking mechanism\n");
#endif
#ifndef NOLOGOHACK
    ErrorF("-logo                  enable logo in screen saver\n");
    ErrorF("nologo                 disable logo in screen saver\n");
#endif
    ErrorF("-nolisten string       don't listen on protocol\n");
    ErrorF("-p #                   screen-saver pattern duration (minutes)\n");
    ErrorF("-pn                    accept failure to listen on all ports\n");
    ErrorF("-nopn                  reject failure to listen on all ports\n");
    ErrorF("-r                     turns off auto-repeat\n");
    ErrorF("r                      turns on auto-repeat \n");
    ErrorF("-s #                   screen-saver timeout (minutes)\n");
#ifdef XCSECURITY
    ErrorF("-sp file               security policy file\n");
#endif
    ErrorF("-su                    disable any save under support\n");
    ErrorF("-t #                   mouse threshold (pixels)\n");
    ErrorF("-terminate             terminate at server reset\n");
    ErrorF("-to #                  connection time out\n");
    ErrorF("-tst                   disable testing extensions\n");
    ErrorF("ttyxx                  server started from init on /dev/ttyxx\n");
    ErrorF("v                      video blanking for screen-saver\n");
    ErrorF("-v                     screen-saver without video blanking\n");
    ErrorF("-wm                    WhenMapped default backing-store\n");
    ErrorF("-x string              loads named extension at init time \n");
#ifdef PANORAMIX
    ErrorF("+xinerama              Enable XINERAMA extension\n");
    ErrorF("-xinerama              Disable XINERAMA extension\n");
#endif
#ifdef XDMCP
    XdmcpUseMsg();
#endif
#ifdef XKB
    XkbUseMsg();
#endif
    ddxUseMsg();
}

/*  This function performs a rudimentary sanity check
 *  on the display name passed in on the command-line,
 *  since this string is used to generate filenames.
 *  It is especially important that the display name
 *  not contain a "/" and not start with a "-".
 *                                            --kvajk
 */
int VerifyDisplayName( d )
char *d;
{
    if ( d == (char *)0 ) return( 0 );  /*  null  */
    if ( *d == '\0' ) return( 0 );  /*  empty  */
    if ( *d == '-' ) return( 0 );  /*  could be confused for an option  */
    if ( *d == '.' ) return( 0 );  /*  must not equal "." or ".."  */
    if ( strchr(d, '/') != (char *)0 ) return( 0 );  /*  very important!!!  */
    return( 1 );
}

/*
 * This function parses the command line. Handles device-independent fields
 * and allows ddx to handle additional fields.  It is not allowed to modify
 * argc or any of the strings pointed to by argv.
 */
void
ProcessCommandLine ( argc, argv )
int	argc;
char	*argv[];

{
    int i, skip;

    defaultKeyboardControl.autoRepeat = TRUE;

#ifdef PART_NET
	PartialNetwork = TRUE;
#endif

    for ( i = 1; i < argc; i++ )
    {
	/* call ddx first, so it can peek/override if it wants */
        if((skip = ddxProcessArgument(argc, argv, i)))
	{
	    i += (skip - 1);
	}
	else if(argv[i][0] ==  ':')  
	{
	    /* initialize display */
	    display = argv[i];
	    display++;
            if( ! VerifyDisplayName( display ) ) {
                ErrorF("Bad display name: %s\n", display);
                UseMsg();
                exit(1);
            }
	}
	else if ( strcmp( argv[i], "-a") == 0)
	{
	    if(++i < argc)
	        defaultPointerControl.num = atoi(argv[i]);
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-ac") == 0)
	{
	    defeatAccessControl = TRUE;
	}
#ifdef MEMBUG
	else if ( strcmp( argv[i], "-alloc") == 0)
	{
	    if(++i < argc)
	        Memory_fail = atoi(argv[i]);
	    else
		UseMsg();
	}
#endif
	else if ( strcmp( argv[i], "-audit") == 0)
	{
	    if(++i < argc)
	        auditTrailLevel = atoi(argv[i]);
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-auth") == 0)
	{
	    if(++i < argc)
	        InitAuthorization (argv[i]);
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "bc") == 0)
	    permitOldBugs = TRUE;
	else if ( strcmp( argv[i], "+bs") == 0)
	    enableBackingStore = TRUE;
	else if ( strcmp( argv[i], "-bs") == 0)
	    disableBackingStore = TRUE;
	else if ( strcmp( argv[i], "c") == 0)
	{
	    if(++i < argc)
	        defaultKeyboardControl.click = atoi(argv[i]);
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-c") == 0)
	{
	    defaultKeyboardControl.click = 0;
	}
	else if ( strcmp( argv[i], "-cc") == 0)
	{
	    if(++i < argc)
	        defaultColorVisualClass = atoi(argv[i]);
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-co") == 0)
	{
	    if(++i < argc)
	        rgbPath = argv[i];
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-core") == 0)
	    CoreDump = TRUE;
	else if ( strcmp( argv[i], "-dpi") == 0)
	{
	    if(++i < argc)
	        monitorResolution = atoi(argv[i]);
	    else
		UseMsg();
	}
#ifdef DPMSExtension
	else if ( strcmp( argv[i], "dpms") == 0)
	    DPMSEnabledSwitch = TRUE;
	else if ( strcmp( argv[i], "-dpms") == 0)
	    DPMSDisabledSwitch = TRUE;
#endif
	else if ( strcmp( argv[i], "-deferglyphs") == 0)
	{
	    if(++i >= argc || !ParseGlyphCachingMode(argv[i]))
		UseMsg();
	}
	else if ( strcmp( argv[i], "-f") == 0)
	{
	    if(++i < argc)
	        defaultKeyboardControl.bell = atoi(argv[i]);
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-fc") == 0)
	{
	    if(++i < argc)
	        defaultCursorFont = argv[i];
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-fn") == 0)
	{
	    if(++i < argc)
	        defaultTextFont = argv[i];
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-fp") == 0)
	{
	    if(++i < argc)
	    {
	        defaultFontPath = argv[i];
	    }
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-help") == 0)
	{
	    UseMsg();
	    exit(0);
	}
#ifdef XKB
        else if ( (skip=XkbProcessArguments(argc,argv,i))!=0 ) {
	    if (skip>0)
		 i+= skip-1;
	    else UseMsg();
	}
#endif
#ifdef RLIMIT_DATA
	else if ( strcmp( argv[i], "-ld") == 0)
	{
	    if(++i < argc)
	    {
	        limitDataSpace = atoi(argv[i]);
		if (limitDataSpace > 0)
		    limitDataSpace *= 1024;
	    }
	    else
		UseMsg();
	}
#endif
#ifdef RLIMIT_NOFILE
	else if ( strcmp( argv[i], "-lf") == 0)
	{
	    if(++i < argc)
	        limitNoFile = atoi(argv[i]);
	    else
		UseMsg();
	}
#endif
#ifdef RLIMIT_STACK
	else if ( strcmp( argv[i], "-ls") == 0)
	{
	    if(++i < argc)
	    {
	        limitStackSpace = atoi(argv[i]);
		if (limitStackSpace > 0)
		    limitStackSpace *= 1024;
	    }
	    else
		UseMsg();
	}
#endif
#ifdef SERVER_LOCK
	else if ( strcmp ( argv[i], "-nolock") == 0)
	{
	  if (getuid() != 0)
	    ErrorF("Warning: the -nolock option can only be used by root\n");
	  else
	    nolock = TRUE;
	}
#endif
#ifndef NOLOGOHACK
	else if ( strcmp( argv[i], "-logo") == 0)
	{
	    logoScreenSaver = 1;
	}
	else if ( strcmp( argv[i], "nologo") == 0)
	{
	    logoScreenSaver = 0;
	}
#endif
	else if ( strcmp( argv[i], "-nolisten") == 0)
	{
            if(++i < argc)
	        protNoListen = argv[i];
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-noreset") == 0)
	{
	    extern char dispatchExceptionAtReset;

	    dispatchExceptionAtReset = 0;
	}
	else if ( strcmp( argv[i], "-p") == 0)
	{
	    if(++i < argc)
	        defaultScreenSaverInterval = ((CARD32)atoi(argv[i])) *
					     MILLI_PER_MIN;
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-pn") == 0)
	    PartialNetwork = TRUE;
	else if ( strcmp( argv[i], "-nopn") == 0)
	    PartialNetwork = FALSE;
	else if ( strcmp( argv[i], "r") == 0)
	    defaultKeyboardControl.autoRepeat = TRUE;
	else if ( strcmp( argv[i], "-r") == 0)
	    defaultKeyboardControl.autoRepeat = FALSE;
	else if ( strcmp( argv[i], "-s") == 0)
	{
	    if(++i < argc)
	        defaultScreenSaverTime = ((CARD32)atoi(argv[i])) *
					 MILLI_PER_MIN;
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-su") == 0)
	    disableSaveUnders = TRUE;
	else if ( strcmp( argv[i], "-t") == 0)
	{
	    if(++i < argc)
	        defaultPointerControl.threshold = atoi(argv[i]);
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-terminate") == 0)
	{
	    extern char dispatchExceptionAtReset;
	    
	    dispatchExceptionAtReset = DE_TERMINATE;
	}
	else if ( strcmp( argv[i], "-to") == 0)
	{
	    if(++i < argc)
		TimeOutValue = ((CARD32)atoi(argv[i])) * MILLI_PER_SECOND;
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-tst") == 0)
	{
	    noTestExtensions = TRUE;
	}
	else if ( strcmp( argv[i], "v") == 0)
	    defaultScreenSaverBlanking = PreferBlanking;
	else if ( strcmp( argv[i], "-v") == 0)
	    defaultScreenSaverBlanking = DontPreferBlanking;
	else if ( strcmp( argv[i], "-wm") == 0)
	    defaultBackingStore = WhenMapped;
#ifdef PANORAMIX
	else if ( strcmp( argv[i], "+xinerama") == 0){
	    noPanoramiXExtension = FALSE;
	}
	else if ( strcmp( argv[i], "-xinerama") == 0){
	    noPanoramiXExtension = TRUE;
	}
#endif
	else if ( strcmp( argv[i], "-x") == 0)
	{
	    if(++i >= argc)
		UseMsg();
	    /* For U**x, which doesn't support dynamic loading, there's nothing
	     * to do when we see a -x.  Either the extension is linked in or
	     * it isn't */
	}
	else if ( strcmp( argv[i], "-I") == 0)
	{
	    /* ignore all remaining arguments */
	    break;
	}
	else if (strncmp (argv[i], "tty", 3) == 0)
	{
	    /* just in case any body is interested */
	    dev_tty_from_init = argv[i];
	}
#ifdef XDMCP
	else if ((skip = XdmcpOptions(argc, argv, i)) != i)
	{
	    i = skip - 1;
	}
#endif
#ifdef XPRINT
	else if ((skip = XprintOptions(argc, argv, i)) != i)
	{
	    i = skip - 1;
	}
#endif
#ifdef XCSECURITY
	else if ((skip = XSecurityOptions(argc, argv, i)) != i)
	{
	    i = skip - 1;
	}
#endif
#ifdef SMART_SCHEDULE
	else if ( strcmp( argv[i], "-dumbSched") == 0)
	{
	    SmartScheduleDisable = TRUE;
	}
	else if ( strcmp( argv[i], "-schedInterval") == 0)
	{
	    if (++i < argc)
	    {
		SmartScheduleInterval = atoi(argv[i]);
		SmartScheduleSlice = SmartScheduleInterval;
	    }
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-schedMax") == 0)
	{
	    if (++i < argc)
	    {
		SmartScheduleMaxSlice = atoi(argv[i]);
	    }
	    else
		UseMsg();
	}
#endif
 	else
 	{
	    ErrorF("Unrecognized option: %s\n", argv[i]);
	    UseMsg();
	    exit (1);
        }
    }
}

#ifdef COMMANDLINE_CHALLENGED_OPERATING_SYSTEMS
static void
InsertFileIntoCommandLine(resargc, resargv, prefix_argc, prefix_argv,
			  filename, suffix_argc, suffix_argv)
    int *resargc;
    char ***resargv;
    int prefix_argc;
    char **prefix_argv;
    char *filename;
    int suffix_argc;
    char **suffix_argv;
{
    struct stat     st;
    FILE           *f;
    char           *p;
    char           *q;
    int             insert_argc;
    char           *buf;
    int             len;
    int             i;

    f = fopen(filename, "r");
    if (!f)
	FatalError("Can't open option file %s\n", filename);

    fstat(fileno(f), &st);

    buf = (char *) xalloc((unsigned) st.st_size + 1);
    if (!buf)
	FatalError("Out of Memory\n");

    len = fread(buf, 1, (unsigned) st.st_size, f);

    fclose(f);

    if (len < 0)
	FatalError("Error reading option file %s\n", filename);

    buf[len] = '\0';

    p = buf;
    q = buf;
    insert_argc = 0;

    while (*p)
    {
	while (isspace(*p))
	    p++;
	if (!*p)
	    break;
	if (*p == '#')
	{
	    while (*p && *p != '\n')
		p++;
	} else
	{
	    while (*p && !isspace(*p))
		*q++ = *p++;
	    /* Since p and q might still be pointing at the same place, we	 */
	    /* need to step p over the whitespace now before we add the null.	 */
	    if (*p)
		p++;
	    *q++ = '\0';
	    insert_argc++;
	}
    }

    buf = (char *) xrealloc(buf, q - buf);
    if (!buf)
	FatalError("Out of memory reallocing option buf\n");

    *resargc = prefix_argc + insert_argc + suffix_argc;
    *resargv = (char **) xalloc((*resargc + 1) * sizeof(char *));
    if (!*resargv)
	FatalError("Out of Memory\n");

    memcpy(*resargv, prefix_argv, prefix_argc * sizeof(char *));

    p = buf;
    for (i = 0; i < insert_argc; i++)
    {
	(*resargv)[prefix_argc + i] = p;
	p += strlen(p) + 1;
    }

    memcpy(*resargv + prefix_argc + insert_argc,
	   suffix_argv, suffix_argc * sizeof(char *));

    (*resargv)[*resargc] = NULL;
} /* end InsertFileIntoCommandLine */


void
ExpandCommandLine(pargc, pargv)
    int *pargc;
    char ***pargv;
{
    int i;

    if (getuid() != geteuid())
	return;

    for (i = 1; i < *pargc; i++)
    {
	if ( (0 == strcmp((*pargv)[i], "-config")) && (i < (*pargc - 1)) )
	{
	    InsertFileIntoCommandLine(pargc, pargv,
					  i, *pargv,
					  (*pargv)[i+1], /* filename */
					  *pargc - i - 2, *pargv + i + 2);
	    i--;
	}
    }
} /* end ExpandCommandLine */
#endif

/* Implement a simple-minded font authorization scheme.  The authorization
   name is "hp-hostname-1", the contents are simply the host name. */
int
set_font_authorizations(authorizations, authlen, client)
char **authorizations;
int *authlen;
pointer client;
{
#define AUTHORIZATION_NAME "hp-hostname-1"
#if defined(TCPCONN) || defined(STREAMSCONN)
    static char result[1024];
    static char *p = NULL;

    if (p == NULL)
    {
	char hname[1024], *hnameptr;
	struct hostent *host;
	int len;
#ifdef XTHREADS_NEEDS_BYNAMEPARAMS
	_Xgethostbynameparams hparams;
#endif

	gethostname(hname, 1024);
	host = _XGethostbyname(hname, hparams);
	if (host == NULL)
	    hnameptr = hname;
	else
	    hnameptr = host->h_name;

	p = result;
        *p++ = sizeof(AUTHORIZATION_NAME) >> 8;
        *p++ = sizeof(AUTHORIZATION_NAME) & 0xff;
        *p++ = (len = strlen(hnameptr) + 1) >> 8;
        *p++ = (len & 0xff);

	memmove(p, AUTHORIZATION_NAME, sizeof(AUTHORIZATION_NAME));
	p += sizeof(AUTHORIZATION_NAME);
	memmove(p, hnameptr, len);
	p += len;
    }
    *authlen = p - result;
    *authorizations = result;
    return 1;
#else /* TCPCONN */
    return 0;
#endif /* TCPCONN */
}

/* XALLOC -- X's internal memory allocator.  Why does it return unsigned
 * long * instead of the more common char *?  Well, if you read K&R you'll
 * see they say that alloc must return a pointer "suitable for conversion"
 * to whatever type you really want.  In a full-blown generic allocator
 * there's no way to solve the alignment problems without potentially
 * wasting lots of space.  But we have a more limited problem. We know
 * we're only ever returning pointers to structures which will have to
 * be long word aligned.  So we are making a stronger guarantee.  It might
 * have made sense to make Xalloc return char * to conform with people's
 * expectations of malloc, but this makes lint happier.
 */

#ifndef INTERNAL_MALLOC

void * 
Xalloc (amount)
    unsigned long amount;
{
    register pointer  ptr;
	
    if ((long)amount <= 0) {
	return (unsigned long *)NULL;
    }
    /* aligned extra on long word boundary */
    amount = (amount + (sizeof(long) - 1)) & ~(sizeof(long) - 1);
#ifdef MEMBUG
    if (!Must_have_memory && Memory_fail &&
	((random() % MEM_FAIL_SCALE) < Memory_fail))
	return (unsigned long *)NULL;
#endif
    if ((ptr = (pointer)malloc(amount))) {
	return (unsigned long *)ptr;
    }
    if (Must_have_memory)
	FatalError("Out of memory");
    return (unsigned long *)NULL;
}

/*****************
 * XNFalloc 
 * "no failure" realloc, alternate interface to Xalloc w/o Must_have_memory
 *****************/

void *
XNFalloc (amount)
    unsigned long amount;
{
    register pointer ptr;

    if ((long)amount <= 0)
    {
        return (unsigned long *)NULL;
    }
    /* aligned extra on long word boundary */
    amount = (amount + (sizeof(long) - 1)) & ~(sizeof(long) - 1);
    ptr = (pointer)malloc(amount);
    if (!ptr)
    {
        FatalError("Out of memory");
    }
    return ((unsigned long *)ptr);
}

/*****************
 * Xcalloc
 *****************/

void *
Xcalloc (amount)
    unsigned long   amount;
{
    unsigned long   *ret;

    ret = Xalloc (amount);
    if (ret)
	bzero ((char *) ret, (int) amount);
    return ret;
}

/*****************
 * XNFcalloc
 *****************/

void *
XNFcalloc (amount)
    unsigned long   amount;
{
    unsigned long   *ret;

    ret = Xalloc (amount);
    if (ret)
	bzero ((char *) ret, (int) amount);
    else if ((long)amount > 0)
        FatalError("Out of memory");
    return ret;
}

/*****************
 * Xrealloc
 *****************/

void *
Xrealloc (ptr, amount)
    register pointer ptr;
    unsigned long amount;
{
#ifdef MEMBUG
    if (!Must_have_memory && Memory_fail &&
	((random() % MEM_FAIL_SCALE) < Memory_fail))
	return (unsigned long *)NULL;
#endif
    if ((long)amount <= 0)
    {
	if (ptr && !amount)
	    free(ptr);
	return (unsigned long *)NULL;
    }
    amount = (amount + (sizeof(long) - 1)) & ~(sizeof(long) - 1);
    if (ptr)
        ptr = (pointer)realloc((char *)ptr, amount);
    else
	ptr = (pointer)malloc(amount);
    if (ptr)
        return (unsigned long *)ptr;
    if (Must_have_memory)
	FatalError("Out of memory");
    return (unsigned long *)NULL;
}
                    
/*****************
 * XNFrealloc 
 * "no failure" realloc, alternate interface to Xrealloc w/o Must_have_memory
 *****************/

void *
XNFrealloc (ptr, amount)
    register pointer ptr;
    unsigned long amount;
{
    if (( ptr = (pointer)Xrealloc( ptr, amount ) ) == NULL)
    {
	if ((long)amount > 0)
            FatalError( "Out of memory" );
    }
    return ((unsigned long *)ptr);
}

/*****************
 *  Xfree
 *    calls free 
 *****************/    

void
Xfree(ptr)
    register pointer ptr;
{
    if (ptr)
	free((char *)ptr); 
}

void
OsInitAllocator ()
{
#ifdef MEMBUG
    static int	been_here;

    /* Check the memory system after each generation */
    if (been_here)
	CheckMemory ();
    else
	been_here = 1;
#endif
}
#endif /* !INTERNAL_MALLOC */


char *
Xstrdup(const char *s)
{
    char *sd;

    if (s == NULL)
	return NULL;

    sd = (char *)Xalloc(strlen(s) + 1);
    if (sd != NULL)
	strcpy(sd, s);
    return sd;
}


char *
XNFstrdup(const char *s)
{
    char *sd;

    if (s == NULL)
	return NULL;

    sd = (char *)XNFalloc(strlen(s) + 1);
    strcpy(sd, s);
    return sd;
}


void
AuditPrefix(f)
    const char *f;
{
    time_t tm;
    char *autime, *s;
    if (*f != ' ')
    {
	time(&tm);
	autime = ctime(&tm);
	if ((s = strchr(autime, '\n')))
	    *s = '\0';
	if ((s = strrchr(argvGlobal[0], '/')))
	    s++;
	else
	    s = argvGlobal[0];
	ErrorF("AUDIT: %s: %d %s: ", autime, getpid(), s);
    }
}

void
AuditF(const char * f, ...)
{
    va_list args;

    AuditPrefix(f);

    va_start(args, f);
    VErrorF(f, args);
    va_end(args);
}

void
FatalError(const char *f, ...)
{
    va_list args;
    static Bool beenhere = FALSE;

    if (beenhere)
	ErrorF("\nFatalError re-entered, aborting\n");
    else
	ErrorF("\nFatal server error:\n");

    va_start(args, f);
    VErrorF(f, args);
    va_end(args);
    ErrorF("\n");
#ifdef DDXOSFATALERROR
    if (!beenhere)
	OsVendorFatalError();
#endif
#ifdef ABORTONFATALERROR
    abort();
#endif
    if (!beenhere) {
	beenhere = TRUE;
	AbortServer();
    } else
	abort();
    /*NOTREACHED*/
}

void
VErrorF(f, args)
    const char *f;
    va_list args;
{
#ifdef DDXOSVERRORF
    if (OsVendorVErrorFProc)
	OsVendorVErrorFProc(f, args);
    else
	vfprintf(stderr, f, args);
#else
    vfprintf(stderr, f, args);
#endif
}

void
VFatalError(const char *msg, va_list args)
{
    VErrorF(msg, args);
    ErrorF("\n");
#ifdef DDXOSFATALERROR
    OsVendorFatalError();
#endif
    AbortServer();
    /*NOTREACHED*/
}

void
ErrorF(const char * f, ...)
{
    va_list args;
    va_start(args, f);
    VErrorF(f, args);
    va_end(args);
}

#ifdef SMART_SCHEDULE

unsigned long	SmartScheduleIdleCount;
Bool		SmartScheduleIdle;
Bool		SmartScheduleTimerStopped;

#ifdef SIGVTALRM
#define SMART_SCHEDULE_POSSIBLE
#endif

#ifdef SMART_SCHEDULE_POSSIBLE
#define SMART_SCHEDULE_SIGNAL		SIGALRM
#define SMART_SCHEDULE_TIMER		ITIMER_REAL
#endif

void
SmartScheduleStopTimer (void)
{
#ifdef SMART_SCHEDULE_POSSIBLE
    struct itimerval	timer;
    
    timer.it_interval.tv_sec = 0;
    timer.it_interval.tv_usec = 0;
    timer.it_value.tv_sec = 0;
    timer.it_value.tv_usec = 0;
    (void) setitimer (ITIMER_REAL, &timer, 0);
    SmartScheduleTimerStopped = TRUE;
#endif
}

Bool
SmartScheduleStartTimer (void)
{
#ifdef SMART_SCHEDULE_POSSIBLE
    struct itimerval	timer;
    
    SmartScheduleTimerStopped = FALSE;
    timer.it_interval.tv_sec = 0;
    timer.it_interval.tv_usec = SmartScheduleInterval * 1000;
    timer.it_value.tv_sec = 0;
    timer.it_value.tv_usec = SmartScheduleInterval * 1000;
    return setitimer (ITIMER_REAL, &timer, 0) >= 0;
#endif
    return FALSE;
}

#ifdef SMART_SCHEDULE_POSSIBLE
void
SmartScheduleTimer (int sig)
{
    int olderrno = errno;

    SmartScheduleTime += SmartScheduleInterval;
    if (SmartScheduleIdle)
    {
	SmartScheduleStopTimer ();
    }
    errno = olderrno;
}
#endif

Bool
SmartScheduleInit (void)
{
#ifdef SMART_SCHEDULE_POSSIBLE
    struct sigaction	act;

    if (SmartScheduleDisable)
	return TRUE;
    
    bzero ((char *) &act, sizeof(struct sigaction));

    /* Set up the timer signal function */
    act.sa_handler = SmartScheduleTimer;
    sigemptyset (&act.sa_mask);
    sigaddset (&act.sa_mask, SMART_SCHEDULE_SIGNAL);
    if (sigaction (SMART_SCHEDULE_SIGNAL, &act, 0) < 0)
    {
	perror ("sigaction for smart scheduler");
	return FALSE;
    }
    /* Set up the virtual timer */
    if (!SmartScheduleStartTimer ())
    {
	perror ("scheduling timer");
	return FALSE;
    }
    /* stop the timer and wait for WaitForSomething to start it */
    SmartScheduleStopTimer ();
    return TRUE;
#else
    return FALSE;
#endif
}
#endif

#ifdef SIG_BLOCK
static sigset_t	PreviousSignalMask;
static int	BlockedSignalCount;
#endif

void
OsBlockSignals (void)
{
#ifdef SIG_BLOCK
    if (BlockedSignalCount++ == 0)
    {
	sigset_t    set;
	
	sigemptyset (&set);
#ifdef SIGALRM
	sigaddset (&set, SIGALRM);
#endif
#ifdef SIGVTALRM
	sigaddset (&set, SIGVTALRM);
#endif
#ifdef SIGWINCH
	sigaddset (&set, SIGWINCH);
#endif
#ifdef SIGIO
	sigaddset (&set, SIGIO);
#endif
#ifdef SIGTSTP
	sigaddset (&set, SIGTSTP);
#endif
#ifdef SIGTTIN
	sigaddset (&set, SIGTTIN);
#endif
#ifdef SIGTTOU
	sigaddset (&set, SIGTTOU);
#endif
	sigprocmask (SIG_BLOCK, &set, &PreviousSignalMask);
    }
#endif
}

void
OsReleaseSignals (void)
{
#ifdef SIG_BLOCK
    if (--BlockedSignalCount == 0)
    {
	sigprocmask (SIG_SETMASK, &PreviousSignalMask, 0);
    }
#endif
}

/*
 * "safer" versions of system(3), popen(3) and pclose(3) which give up
 * all privs before running a command.
 *
 * This is based on the code in FreeBSD 2.2 libc.
 *
 * XXX It'd be good to redirect stderr so that it ends up in the log file
 * as well.  As it is now, xkbcomp messages don't end up in the log file.
 */

int
System(command)
    char *command;
{
    int pid, p;
#ifdef SIGCHLD
    void (*csig)(int);
#endif
    int status;

    if (!command)
	return(1);

#ifdef SIGCHLD
    csig = signal(SIGCHLD, SIG_DFL);
#endif

#ifdef DEBUG
    ErrorF("System: `%s'\n", command);
#endif

    switch (pid = fork()) {
    case -1:	/* error */
	p = -1;
    case 0:	/* child */
	setgid(getgid());
	setuid(getuid());
	execl("/bin/sh", "sh", "-c", command, (char *)NULL);
	_exit(127);
    default:	/* parent */
	do {
	    p = waitpid(pid, &status, 0);
	} while (p == -1 && errno == EINTR);
	
    }

#ifdef SIGCHLD
    signal(SIGCHLD, csig);
#endif

    return p == -1 ? -1 : status;
}

static struct pid {
    struct pid *next;
    FILE *fp;
    int pid;
} *pidlist;

pointer
Popen(command, type)
    char *command;
    char *type;
{
    struct pid *cur;
    FILE *iop;
    int pdes[2], pid;

    if (command == NULL || type == NULL)
	return NULL;

    if ((*type != 'r' && *type != 'w') || type[1])
	return NULL;

    if ((cur = (struct pid *)xalloc(sizeof(struct pid))) == NULL)
	return NULL;

    if (pipe(pdes) < 0) {
	xfree(cur);
	return NULL;
    }

    switch (pid = fork()) {
    case -1: 	/* error */
	close(pdes[0]);
	close(pdes[1]);
	xfree(cur);
	return NULL;
    case 0:	/* child */
	setgid(getgid());
	setuid(getuid());
	if (*type == 'r') {
	    if (pdes[1] != 1) {
		/* stdout */
		dup2(pdes[1], 1);
		close(pdes[1]);
	    }
	    close(pdes[0]);
	} else {
	    if (pdes[0] != 0) {
		/* stdin */
		dup2(pdes[0], 0);
		close(pdes[0]);
	    }
	    close(pdes[1]);
	}
	execl("/bin/sh", "sh", "-c", command, (char *)NULL);
	_exit(127);
    }

    /* Avoid EINTR during stdio calls */
    OsBlockSignals ();
    
    /* parent */
    if (*type == 'r') {
	iop = fdopen(pdes[0], type);
	close(pdes[1]);
    } else {
	iop = fdopen(pdes[1], type);
	close(pdes[0]);
    }

    cur->fp = iop;
    cur->pid = pid;
    cur->next = pidlist;
    pidlist = cur;

#ifdef DEBUG
    ErrorF("Popen: `%s', fp = %p\n", command, iop);
#endif

    return iop;
}

int
Pclose(iop)
    pointer iop;
{
    struct pid *cur, *last;
    int pstat;
    int pid;

#ifdef DEBUG
    ErrorF("Pclose: fp = %p\n", iop);
#endif

    fclose(iop);

    for (last = NULL, cur = pidlist; cur; last = cur, cur = cur->next)
	if (cur->fp == iop)
	    break;
    if (cur == NULL)
	return -1;

    do {
	pid = waitpid(cur->pid, &pstat, 0);
    } while (pid == -1 && errno == EINTR);

    if (last == NULL)
	pidlist = cur->next;
    else
	last->next = cur->next;
    xfree(cur);

    /* allow EINTR again */
    OsReleaseSignals ();
    
    return pid == -1 ? -1 : pstat;
}


/*
 * CheckUserParameters: check for long command line arguments and long
 * environment variables.  By default, these checks are only done when
 * the server's euid != ruid.  In 3.3.x, these checks were done in an
 * external wrapper utility.
 */

/* Consider LD* variables insecure? */
#ifndef REMOVE_ENV_LD
#define REMOVE_ENV_LD 1
#endif

/* Remove long environment variables? */
#ifndef REMOVE_LONG_ENV
#define REMOVE_LONG_ENV 1
#endif

/*
 * Disallow stdout or stderr as pipes?  It's possible to block the X server
 * when piping stdout+stderr to a pipe.
 *
 * Don't enable this because it looks like it's going to cause problems.
 */
#ifndef NO_OUTPUT_PIPES
#define NO_OUTPUT_PIPES 0
#endif


/* Check args and env only if running setuid (euid == 0 && euid != uid) ? */
#ifndef CHECK_EUID
#define CHECK_EUID 1
#endif

/*
 * Maybe the locale can be faked to make isprint(3) report that everything
 * is printable?  Avoid it by default.
 */
#ifndef USE_ISPRINT
#define USE_ISPRINT 0
#endif

#define MAX_ARG_LENGTH          128
#define MAX_ENV_LENGTH          256
#define MAX_ENV_PATH_LENGTH     2048	/* Limit for *PATH and TERMCAP */

#if USE_ISPRINT
#include <ctype.h>
#define checkPrintable(c) isprint(c)
#else
#define checkPrintable(c) (((c) & 0x7f) >= 0x20 && ((c) & 0x7f) != 0x7f)
#endif

enum BadCode {
    NotBad = 0,
    UnsafeArg,
    ArgTooLong,
    UnprintableArg,
    EnvTooLong,
    OutputIsPipe,
    InternalError
};

#define ARGMSG \
    "\nIf the arguments used are valid, and have been rejected incorrectly\n" \
      "please send details of the arguments and why they are valid to\n" \
      "XFree86@XFree86.org.  In the meantime, you can start the Xserver as\n" \
      "the \"super user\" (root).\n"   

#define ENVMSG \
    "\nIf the environment is valid, and have been rejected incorrectly\n" \
      "please send details of the environment and why it is valid to\n" \
      "XFree86@XFree86.org.  In the meantime, you can start the Xserver as\n" \
      "the \"super user\" (root).\n"

void
CheckUserParameters(int argc, char **argv, char **envp)
{
    enum BadCode bad = NotBad;
    int i = 0, j;
    char *a, *e = NULL;

#if CHECK_EUID
    if (geteuid() == 0 && getuid() != geteuid())
#endif
    {
	/* Check each argv[] */
	for (i = 1; i < argc; i++) {
	    if (strlen(argv[i]) > MAX_ARG_LENGTH) {
		bad = ArgTooLong;
		break;
	    }
	    a = argv[i];
	    while (*a) {
		if (checkPrintable(*a) == 0) {
		    bad = UnprintableArg;
		    break;
		}
		a++;
	    }
	    if (bad)
		break;
	}
	if (!bad) {
	    /* Check each envp[] */
	    for (i = 0; envp[i]; i++) {

		/* Check for bad environment variables and values */
#if REMOVE_ENV_LD
		while (envp[i] && (strncmp(envp[i], "LD", 2) == 0)) {
#ifdef ENVDEBUG
		    ErrorF("CheckUserParameters: removing %s from the "
			   "environment\n", strtok(envp[i], "="));
#endif
		    for (j = i; envp[j]; j++) {
			envp[j] = envp[j+1];
		    }
		}
#endif   
		if (envp[i] && (strlen(envp[i]) > MAX_ENV_LENGTH)) {
#if REMOVE_LONG_ENV
#ifdef ENVDEBUG
		    ErrorF("CheckUserParameters: removing %s from the "
			   "environment\n", strtok(envp[i], "="));
#endif
		    for (j = i; envp[j]; j++) {
			envp[j] = envp[j+1];
		    }
		    i--;
#else
		    char *eq;
		    int len;

		    eq = strchr(envp[i], '=');
		    if (!eq)
			continue;
		    len = eq - envp[i];
		    e = malloc(len + 1);
		    if (!e) {
			bad = InternalError;
			break;
		    }
		    strncpy(e, envp[i], len);
		    e[len] = 0;
		    if (len >= 4 &&
			(strcmp(e + len - 4, "PATH") == 0 ||
			 strcmp(e, "TERMCAP") == 0)) {
			if (strlen(envp[i]) > MAX_ENV_PATH_LENGTH) {
			    bad = EnvTooLong;
			    break;
			} else {
			    free(e);
			}
		    } else {
			bad = EnvTooLong;
			break;
		    }
#endif
		}
	    }
	}
#if NO_OUTPUT_PIPES
	if (!bad) {
	    struct stat buf;

	    if (fstat(fileno(stdout), &buf) == 0 && S_ISFIFO(buf.st_mode))
		bad = OutputIsPipe;
	    if (fstat(fileno(stderr), &buf) == 0 && S_ISFIFO(buf.st_mode))
		bad = OutputIsPipe;
	}
#endif
    }
    switch (bad) {
    case NotBad:
	return;
    case UnsafeArg:
	ErrorF("Command line argument number %d is unsafe\n", i);
	ErrorF(ARGMSG);
	break;
    case ArgTooLong:
	ErrorF("Command line argument number %d is too long\n", i);
	ErrorF(ARGMSG);
	break;
    case UnprintableArg:
	ErrorF("Command line argument number %d contains unprintable"
		" characters\n", i);
	ErrorF(ARGMSG);
	break;
    case EnvTooLong:
	ErrorF("Environment variable `%s' is too long\n", e);
	ErrorF(ENVMSG);
	break;
    case OutputIsPipe:
	ErrorF("Stdout and/or stderr is a pipe\n");
	break;
    case InternalError:
	ErrorF("Internal Error\n");
	break;
    default:
	ErrorF("Unknown error\n");
	ErrorF(ARGMSG);
	ErrorF(ENVMSG);
	break;
    }
    FatalError("X server aborted because of unsafe environment\n");
}

/*
 * CheckUserAuthorization: check if the user is allowed to start the
 * X server.  This usually means some sort of PAM checking, and it is
 * usually only done for setuid servers (uid != euid).
 */

#ifdef USE_PAM
#include <security/pam_appl.h>
#include <security/pam_misc.h>
#include <pwd.h>
#endif /* USE_PAM */

void
CheckUserAuthorization()
{
#ifdef USE_PAM
    static struct pam_conv conv = {
	misc_conv,
	NULL
    };

    pam_handle_t *pamh = NULL;
    struct passwd *pw;
    int retval;

    if (getuid() != geteuid()) {
	pw = getpwuid(getuid());
	if (pw == NULL)
	    FatalError("getpwuid() failed for uid %d\n", getuid());

	retval = pam_start("xserver", pw->pw_name, &conv, &pamh);
	if (retval != PAM_SUCCESS)
	    FatalError("pam_start() failed.\n"
			"\tMissing or mangled PAM config file or module?\n");

	retval = pam_authenticate(pamh, 0);
	if (retval != PAM_SUCCESS) {
	    pam_end(pamh, retval);
	    FatalError("PAM authentication failed, cannot start X server.\n"
			"\tPerhaps you do not have console ownership?\n");
	}

	retval = pam_acct_mgmt(pamh, 0);
	if (retval != PAM_SUCCESS) {
	    pam_end(pamh, retval);
	    FatalError("PAM authentication failed, cannot start X server.\n"
			"\tPerhaps you do not have console ownership?\n");
	}

	/* this is not a session, so do not do session management */
	pam_end(pamh, PAM_SUCCESS);
    }
#endif
}
